This invention relates to a process for the preparation of modified polyisocyanates in which organic polyisocyanates are reacted with a specific type of organic polyamine.
The conversion of polyisocyanates to ureas or polyureas by reacting a polyisocyanate with primary or secondary amines is well known. This reaction is much more vigorous than a reaction of polyisocyanates in which primary or secondary alcohols are used rather than amines (particularly when the amine reaction is carried out without a diluent). The heat generated during the conversion frequently makes it difficult to control the temperature of the reaction (see, for example, British Pat. No. 1,263,609).